Practice Relating to Rule 7. The Principle of Distinction between Civilian Objects and Military Objectives
Section E. Attacks against civilian means of transportation
New Zealand’s Military Manual (1992) states:
Civilian vessels, aircraft, vehicles and buildings may be lawfully attacked if they contain combatant personnel or military equipment or supplies or are otherwise associated with combat activity inconsistent with their civilian status and if collateral damage would not be excessive under the circumstances.
The manual further states:
Civil aircraft (including State aircraft which are not military aircraft) in flight should not be attacked. They are presumed to be carrying civilians who may not be made the object of direct attack. If there is doubt as to the status of a civil aircraft, it should be called upon to clarify that status. If it fails to do so, or is engaged in non-civil activities, such as ferrying troops, it may be attacked. Civil aircraft should avoid entering areas which have been declared combat zones by the belligerents, since this increases the risk of their being attacked.